Machine for production of high voltage fuses without insulating chaplet and with melting elements of different cross section

ABSTRACT

A machine for production of high voltage fuses without holders for the fuse elements comprising a clamping device for supporting a hollow fuse body below a hopper which is adapted for introducing sand into the fuse body. A platform supports the hopper and is adapted for raising and lowering the hopper so as to introduce and retract the same into and from the fuse body. Melting material which is to form the fuse element is coiled into the fuse body and the fuse body is filled with sand which is compacted therein around the coiled melting material. As a consequence, the melting material is supported within the fuse body in the sand without need for a holder for the fuse element.

1451 Aug. 27, 1974 United States Patent 1191 Aleksandar et al.

3 49l,425 l/l970 McConnell et: al. 29/203 R MACHINE FOR PRODUCTION OF HIGH VOLTAGE FUSES WITHOUT INSULATING CHAPLET AND WITH MELTING Primary ExaminerThomas H. Eager ELEMENTS OF DIFFERENT CROSS Attorney, Agent, or Firm-Eric H. Waters SECTION ABSTRACT Inventors: Manoilov Aleksandar, Marjana Baruna 47; Karisik Mustafa, Bratstva i Jedinstva, both of Sarajevo, Yugoslavia Jan. 29, 1973 221 Filed:

21 Appl. No.: 327,850

52 u.s.c1......... 29/203R 51 1m. (:1. uos 13/00 58 Field of Search... 29/203 R, 203 P, 622, 203 D the coiled melting material. As a consequence, the melting material is supported within the fuse body in the sand without need for a holder for the fuse element.

[56] References Cited UNITED STATES PATENTS 3.203081 8/1965 29/203 R 3.404.447 10/1968 9 CIaImS, 2 Drawing Figures Chanowitz.........r...........,. 29/622 X MACHINE FOR PRODUCTION OF HIGH VOLTAGE FUSES WITHOUT INSULATING CHAPLET AND WITH MELTING ELEMENTS OF DIFFERENT CROSS SECTION I BACKGROUND AND NATURE OF THE INVENTION In theory, fuses without chaplets are ideal as the whole medium is used for are quenching. During eff1 ciency tests with fuses produced according to the in vention, this was confirmed. An overvoltage problem was solved by mixing quartz sand constituents of different granule sizes.

High voltage fuses without star chaplets have heretofore been produced in the laboratory, but all former attempts to industrialize the production of such fuses were unsuccessful, as the assembling was insecure and it was impossible to control the layout of wires inside the cartridge.

The machine according to the invention represents the first instance of industrialized production of high voltage fuses without chaplets.

The new .high voltage fuse melting elements can be either of round cross section, in the form of spiral wire, or can be a slab in cross section. Two different types of the new machines for production of high voltage fuses without chaplets are exemplified depending on the chosen form of the melting element. One machine is shown in FIG. 1 where the melting element is a perforated strip; another type is shown in FIG. 2, where the melting element is a wire.

The construction is principally based on perforated laminas. which are preferred mainly for higher power fuses. Another reason for using perforated laminas is that overvoltage cannot be affected by the variation of the round wire cross section.

In the drawing:

FIG. 1 is a vertical sectional sideview of a first embodiment of this invention; and

FIG. 2 is a similar view of a second embodiment.

Reference will first be made to FIG. 1.

In order to form spirals of melting lamina strips to provide fuses, the following steps are taken: clamping a strip to a socket, rotating the pipe with reticular socket pipe and transporting laminas. After completing of the spirals, the fuse is mounted, sand is poured into it at the same time the spiral is wound from the socket, and the sand is rammed by vibration without rotation.

A preferred machine for such production of fuses, with slab melting elements, according to the invention, is shown in FIG. 1. The machine comprises a base 18 with a post 27 having slidably positioned thereon a platform 12 rigidly supporting a hopper 5. A platform 13 is slidably mounted on post 27 and supports a shaft 8 adapted for driving a vertical spindle l9 rotatably mounted on platform 13, the shaft being driven by electromotor 22 through pulley system 20, 21. Post 27 also slidably supports a platform 11 which supports a socket 6 for a vertical pipe 7 slidably mounted in platform 13. Secured to platform 11 is a vertical rod 24 with holes 25 for adjusting the height of platform 11 relative to a platform 14. The platform 14 supports a vibrator 23 below hopper 5 and socket 6 and the platform 14 is provided with a clamp 26 having a fuse 1 positioned thereon.

Vibrator 23 and electromotor 22 are connected via a switch panel 30 for different operating conditions 32, 33, 34, 35, as is known to those skilled in the art. The switch panel has a power cord 31.

On the base 18 is also placed a conveyor 10 for transporting melting laminas 2, made from coils connected to socket 6 joined with network connecting pieces 9. Driving the winding of a coil, pipe 7 is inserted therein and hopper 5 is inside pipe 7; for transporting a laminar coil, by the conveyor, pipe 7 is retracted from the coil. For transporting the coil by the conveyor, downward vertical motions of platforms 11, 14 is effected, while platform 12 is raised. In order to obtain these relative motions, one half of the spindle length, in regions 17, has a right hand thread and the other spindle half has a left hand thread for raising and lowering platforms 12, 11, respectively, and for uncoupling, by the raising of platform 12, a gear wheel 15 fixed to platform 12 from a gear wheel 16 on pipe 7 and from a pinion 36 on the shaft 8. The movement of platform 11 is limited by stops 28 and 29.

The machine operates in the following manner:

Initially, platform 12 and hopper 5 are maximally raised whereas platform 11 is maximally lowered to the edge 4 of pipe 7. In that position the network connecting piece 9 is inside the pipe 7. The end of a melting lamina 2, transported from the coils by the conveyor 10, is then connected to the socket 6. By operating the motor 22, the hopper 5 on platform 11 moves downwardly and the platform 11 upwardly; the hopper 5, pipe 7, socket 6 and network connecting piece 9 being at the same time rotated, thus causing the winding of the spiral on the network connecting piece 9 which is now pulled over the pipe 7. When a spiral hasbeen wound along the length of the connecting piece 9, the operation of the motor is stopped, for example by a conventional limit switch (not shown).

Laminas are removed from the coils and their ends are connected to the end of the network connecting piece 9, as by gluing, cementing or soldering; then the vibrator 23 with clamp 26 is moved aside and the fuse 1 is pulled over pipe 7 and the network connecting piece 9. Vibrator 23 is then returned to the starting point and the fuse is fixed thereto, to the bottom of which having been previously connected the ends of the laminas, which have been connected to the network connecting piece. The'hopper is then filled with a defined amount of sand 3, which is sufficient for one charge of the fuse. Gear wheel 15 is moved into an upper position, so that it is disengaged from the gear wheel 16, and thus the rotation is stopped.

The vibrator is then switched on; vibrator 23 and platforms 11 and 14 begin to move downwardly, and platform 12 with hopper 5 upwardly. The hopper retracts the network connecting piece 9 and the spirals of melting elements 2 slip down into the sand so as to be dug therein and rammed in place. When the hopper reaches its upper position, the filling of the fuse is completed and the latter is removed and sent for further mounting.

For forming fuses with melting wire spirals, the following steps are required: fixing the wires to an indicator, rotating the fuse, transporting the wires for the fuse, and charging and ramming the sand into the fuse. For the first step it is necessary to have free space for stretching the spiral wire by hand for fixing the spiral to an indicator. Accordingly, sufficient working space and visibility are needed to enable workers to work in normal positions using the required tools.

The indicator wire should set the indicator spring free, during a short-circuit; in view of which the wire has to be stretched. This construction is based on the fact that the indicator wire will be used by the are along its length.

In order to obtain melting element spirals in the fuses with proper geometric form and sufficiently stretched in the rammed sand, the rotating of the fuse, the transporting of the wire, charging and ramming of the sand are critically dependent upon the operations and working sequences, described hereinafter.

The fuse turns once for each screw pitch. For this ratio, wire of properly defined length, which forms an axial spiral of given diameter, is charged by the conveyor.

Driving of the wire pinch rolls is adjusted so that, during idle operation (back pull), when the platform moves downwardly, these rolls do not transport the wire, which means that it is necessary to enable the driving of the wire transport to be automatically divided at this moment, by cogged gears, Technically the most critical question resides in the problem of wire charging and discharging, as silver wire of 0.08 to 0.3 mm diameter is to be forced or guided through a pipe of predetermined clearance, length and curvatures. The problem of charging and discharging the wire is solved by suitably chosen pinch rolls and guides. Sand charging is provided by the hopper unit, which is charged with the amount of sand sufficient for filling one fuse. Changes in the size of the sand granules do not affect the discharging and charging characteristics of the sand to any appreciable extent.

The machine according to FIG. 2 is provided so as to satisfy all the above mentioned requirements. The unit below the lower fuse top transmits the vibrations from the vibrator to the fuse; at the same time it rotates together with the fuse during the filling. The elements of thefu se cmfiir'ig'rrbifi'ihe indicator side are previously positioned on this unit. Pivotable linkage between the fuse and this unit is obtained by admission of the fuse screw top into this unit. The construction of this embodiment of the machine is such that these basic requirements are realized. regarding the filling of the high voltage fuses. according to the previously given melting wire spiral layout in the fuse. as: stretching the fuse device in auxiliary processes in connection with mounting the indicator; connecting the melting wires on one side and the other; vibration of the fuse during rotation without transmitting the vibrations to the device frame and the rest of the mechanism; rotation of the fuse in the corresponding direction and by the cor responding speed; subsequent filling of the fuse with the melting wire from the coil over the roll and guides to the fuse at a corresponding speed; maximum capacity of the device being made dependent on charging of the fuse with sand; limiting of the path; electric blocking of individual and collective movements and actuations: removing of the filled fuse; and back pull without shifting melting wire or transmitting vibrations.

Gear wheels 16 are placed inside a box 18' for transmission of the drive of electromotor 22' through pulley systems 20', 21' to a shaft 8' the rotation of which is transmitted through gear wheels 19 and 17 to a shaft 15 with a guiding connecting piece 9, to roll wire conveyor 10 and through the gear wheels 19', 24' to shaft 25' with clamp 26 and fuse l. Vibrator 23 is placed within the box 18 and is connected, together with electromotor 22', to the switch panel 30 with the controls 32, 33, 34, 35 for different operations. The switch panel has a power cord 31.

Shaft 8 with fixed gear wheel 19 has a threaded end 36 engaged with a thread in socket 27' secured to platform 37 for moving the platform upwardly and downwardly, the path of which is limited by stops 28, 29. The hopper 5 with transport pipes 14 is fixed by a clamp 7 on platform 37.

The machine as shown in H6. 2, for making melting wire fuses operates in the following manner: the fuse 1' is first fixed to clamp 26, and inside the fuse, the hopper 5' is located with transport pipes 14, and the melting wires are fixed to the fuse bottom. The hopper is charged with the correct amount of quartz sand 3. When switching on the electromotor 22, the vibrator 23' starts the filling of the fuse. While rotating the fuse 1 from motor 22, the hopper 5 with transport pipes 14 moves upwardly, the conveyor 10' forces the wires from coil 13 through the guides 11 and 12' to the pipes 14', causing spiral windings of the wires in the sand which is at the same time being rammed by vibrator 23'. Upon completion of the filling thereof, the fuse is removed. During back pulling, the conveyor does not transport the wires, due to the provision of a pawl and ratchet gear 16.

The machines for making high voltage fuses without chaplets have been tested as to the parameters essential for the quality of the product. All tests gave satisfactory results.

What we claim is:

l. A machine for production of fuses without holders for the fuse elements, said machine comprising a clamping means for supporting a hollow fuse body, a hopper supported above said clamping means, said hopper serving for introduction of sand into the fuse body, a platform supporting said hopper, means for raising and lowering said platform and introducing and retracting said hopper into and from said fuse body, a supply of melting material to form a fuse element, means for coiling said melting material into said fuse body and vibrator means for compacting the sand in the fuse body around the coiled melting material.

2. A machine as claimed in claim 1 wherein said means for raising and lowering said platform comprises a drive motor, and a rotatable shaft coupled to said drive motor and threadably engaged with said platform.

3. A machine as claimed in claim 1 comprising a base with a support beam on which said platform is slidably mounted, a second platform slidably mounted on said support beam and supporting said vibrator means, said means for raising and lowering the first said platform comprising a drive motor, and means coupled to said drive motor moving said platforms, in concert, on said support beam respectively towards and away from one another.

4. A machine as claimed in claim 3 wherein said means for moving said platform comprises a shaft having opposite ends with opposite direction threads on said ends. said ends of the shaft being respectively threaded in said platforms.

5. A machine as claimed in claim 3 wherein said means for coiling the melting material into the fuse body comprises a socket rotatably mounted on the sec ond platform adapted for receiving the end of melting material to be coiled in the fuse body, a rotatable drive pipe drivingly engaged with said socket, said drive pipe being drivingly coupled said drive motor. a network connecting piece connected to said hopper and adaptedfor being disposed around said pipe. said socket caus-; ing winding of the melting material around said con-, necting piece. said hopper causing said connecting piece to be withdrawn from the wound melting material while the fuse body is lowered when said platforms are moved away from one another.

6. A machine as claimed in claim 2 comprising a box containing said vibrator means, said shaft extending into said box and including a fixed gear thereon, and a plurality of further gears in said box in mesh with said fixed gear and respectively coupled to said vibrator means and to said means for coiling the melting material.

7. A machine as claimed in claim 6 wherein said hopper is fixed to said platform.

8. A machine as claimed in claim 6 wherein said means for coiling the melting material comprises a transport pipe passing through said hopper into the fuse body. and means driven in rotation by one of said further gears and engaging the melting material to pass the same through said transport pipe.

9. A machine as claimed in claim 8 wherein the melting material coming from the transport pipe is secured to said fuse body, means being driven by another of said further gears to effect rotation of the fuse body and formation of coils of the melting material delivered from the transport pipe. 

1. A machine for production of fuses without holders for the fuse elements, said machine comprising a clamping means for supporting a hollow fuse body, a hopper supported above said clamping means, said hopper serving for introduction of sand into the fuse body, a platform supporting said hopper, means for raising and lowering said platform and introducing and retracting said hopper into and from said fuse body, a supply of melting material to form a fuse element, means for coiling said melting material into said fuse body and vibrator means for compacting the sand in the fuse body around the coiled melting material.
 2. A machine as claimed in claim 1 wherein said means for raising and lowering said platform comprises a drive motor, and a rotatable shaft coupled to said drive motor and threadably engaged with said platform.
 3. A machine as claimed in claim 1 comprising a base with a support beam on which said platform is slidably mounted, a second platform slidably mounted on said support beam and supporting said vibrator means, said means for raising and lowering the first said platform comprising a drive motor, and means coupled to said drive motor moving said platforms, in concert, on said support beam respectively towards and away from one another.
 4. A machine as claimed in claim 3 wherein said means for moving said platform comprises a shaft having opposite ends with opposite direction threads on said ends, said ends of the shaft being respectively threaded in said platforms.
 5. A machine as claimed in claim 3 wherein said means for coiling the melting material into the fuse body comprises a socket rotatably mounted on the second platform adapted for receiving the end of melting material to be coiled in the fuse body, a rotatable drive pipe drivingly engaged with said socket, said drive pipe being connected to said drive motor, a network connecting piece connected to said hopper and adapted for being disposed around said pipe, said socket causing winding of the melting material around said connecting piece, said hopper causing said connecting piece to be withdrawn from the wound melting material while the fuse body is lowered when said platforms are moved away from one another.
 6. A machine as claimed in claim 2 comprising a box containing said vibrator means, said shaft extending into said box and including a fixed gear thereoN, and a plurality of further gears in said box in mesh with said fixed gear and respectively coupled to said vibrator means and said means for coiling the melting material.
 7. A machine as claimed in claim 6 wherein said hopper is fixed to said platform.
 8. A machine as claimed in claim 6 wherein said means for coiling the melting material comprises a transport pipe passing through said hopper into the fuse body, and means driven in rotation by one of said further gears and engaging the melting material to pass the same through said transport pipe.
 9. A machine as claimed in claim 8 wherein the melting material coming from the transport pipe is secured to said fuse body, means being driven by another of said further gears to effect rotation of the fuse body and formation of coils of the melting material delivered from the transport pipe. 